Automatically-releasable skid chock



July 7, 1925. I

. S. S. HAWKINS AUTOMATICALLY RELEASABLE SKID CHQCK Filed Dec. 18. 1924 the general object of the invention is to Patented July 7, 19 25.

1,544,576 UNITED STATES PATENT OFFICE.

SAMUEL S. HAWKINS, OF JACKSONVILLE, ALABAMA. AUTOMATIGALLYFRELEASABLE SKID CHOOSE.

' Application filed December 18, 1924. Serial 170. 766,792.

To all whom it may comm:

Be it known that I, SAMUEL S. HAWKINS, a citizen of the United States residing at Jacksonville, in the county of Calhoun and State of Alabama, have invented certain new and useful Improvements in Automatically-Releasable Skid Chocks, of which the following is a specification, reference being had to the accompanying drawings.

This invention relates to aeroplanes, and

provide a device which will impede the forward movement of an aeroplane when it is starting until the propellers have reached a predetermined speed, the device then being automatically tripped, as it were, and the machine then going forward and rising.

It is necessary in starting that an aeroplane should take a relatively long run over the ground before it can get up speed enough to rise, and the object of the present invention is to provide'a device which will impede the forward movement of the plane until the propellers have reached a speed which will be sufiicient to cause the machine to lift almost immediately, thus doing away with the long starting run and permitting the machine to rise in a short space and over relatively rough ground or in fields where there is high grass or something of this character which will impede the forward movement of the plane.

A further object is to provide a device of this character which is so constructed that it may bev adjusted so that it will automatically trip when the speed of the propellers reaches any desired point and thus so that the machine will not trip until the propeller reaches a speed of twenty, thirty or forty miles an hour more or less, and which will trip automatically so that the aviator will not have to trip the device himself.

A still further object is to provide a deire of this character which will, to a certain extent, act to kick the machine oil the ground or lift it as the machine starts.

My invention-is illustrated in the accompanying drawin wherein Figure 1 is a ragmentary elevation of the forward end of an aeroplane showing the landin gear thereof and my invention applied t ereto;

Figure 2 is afront tion shown in Figure 1; p

Figure 3 is a fragmenta yeleva i n howview of the construc:

. ing the manner ing wheels, 14 the .ties are angularly in which the machine moves forward and trips the chock;

Figure 4 is a fragmentary side elevation 4 showing a modification, the device being in its holding position;

Figure 5 is a like view'to Figure 4 but showing the device in its released position; Referring to this drawing, and particularly to Figure 1, it will be seen that I have illustrated so much of an ordinary aero-' plane as is necessary to disclose my invention. In the drawing, 10 designates the bottom of the fuselage of the aeroplane, 11 and 12 the upper and lower planes, 13 the landusual struts supporting the landing wheels, and 15.the axle of the landing wheels. Disposed on each side of the landing gear are the bars 17, each of which is formed upon its upper face with a series of recesses 18 adapted to receive the axle 15. These bars 17 are connected at their forward ends by means of a transverse bar 19 which is angularly bent at its extremities and pivotally or otherwise engaged with the bars 17. These bars 17 are preferably formed at their forward extremities with sharp-pointed, relatively wide shoes 20, the points of which are adapted to engage the ground and the shoes being relatively wide so that these extremities of the bars 17 will not mire down. Preferably the bars 17 are also formed with spurs 21 disposed at a slight angle to the bars 17 and adapted to enga e the ground. This is necessary because w en in actual use the bars 17 are disposed at an acute angle to the ground.

Pivotally connected to the rear ends of the bars 17 are the. links 22, which at their upper ends are pivotally connected at 23 to l'nks 24, which in turn extend rearward and are pivoted upon pins 25 or like elements projecting out from the floor'of the fuselage. The bars 22 are preferably connected by means of a transverse bar 26, whose extremibent. Connected to the bar 26 is a spring 27 which extends forward and is in turn connected porting member as, for instance, the vertical member 28 projecting up throu h the bottom of the fusela e. The rear, en s of the bars 24 roject b ow the bottom of the fuselage and are connected by resilient means 29 which will resist upward movement b bearing against the bottom of the fuse age so that a th f rward ends of e s 24 are to any suitable supof the shifted downward, this spring bearing the landing wheels and exterior to each landagainst. the bottom of the fuselage will ing wheel a link which is pivoted upon yieldingly resist this downward movement the axle. The free end of this link is pivotorward ends of the bars, The whole ally connected by a bolt 31 to the bar 32 urpose of the springs 27 and 29 is to yieldwhich at its lower end is pointed, as at 33. lngly resist the downward movement of the These bars 32 are the equivalent of the bars supporting members 24. 17 previously described and may be formed In practice, before the aeroplane starts in any suitable manner and constitute off, the bars 17 are brought forward to the chocks. Each bar or chock 32 is formed position shown in Figure 1 and the axle 14 with a plurality of openings 34 through 7 is engaged in any one. of the notches 18. If which the bolt 31 may pass, these openings it is engaged in the notch a, the aeroplane being arrangedin longitudinal series. Each will be impeded in its forward movement bar or chock-32 is formed with an car 35 until a relatively low rate of speed has been and this car carries a pin 36 to which a secured by the propellers. If it is laced in spring 37 is connected, this spring extending the notch b a higher rate of spec will be upward to the fuselage and being connected necessary before the detainer will trip, as to the fuselage in any suitable manner. before stated, and a still higher rate of speed In the'use of this device, the bolts 31 are will have to be developed in order for the adjusted in the proper holes 34 to suit the device to be tripped if the axle is disposed speed at. which it is desired to start the aeroin the notches 0. When the bars 17 are .displane. The forward ends of the chocks 32 posed forward and downward, as before deare forced into the ground and impede the scribed, the pointed extremities 20 and 21 of forward movement of the aeroplane, the the bars will engage with the ground. The springs 37 acting, as shown in Figure4, to propeller is then started and in order for hold these chocks forced into the ground. the machine to move forward it will have to When the speed of the aeroplane has inlift the bars 17 to a nearly vertical position creased the proper amount it will move forso that the propeller must have developed a ward and be simultaneously lifted in order certain rate of speed before there will be to pass over the chocks, the chocks turning sufficient force to urge the machine forward to the position shown in full lines in Figure against the impediment afiorded by the bars 5 and eventually to the position shown in 17 and the cross bar 19. When this speed dotted lines in Figure 5, when theyare fully has been developed, the member 17 will dropped move into nearly a vertical position, and the It will be seen that the construction shown front wheels of the landing gear will ump in Figures 4 and 5 operates in practically the obstruction, as it might be termed, and the same manner as the construction shown the machine will be lifted partly into the air in Figures 1 and 2, and that when the maand will start tofly after a relatively short chine has secured sufficient impetus it will run, the length of this run being less, of be forced forward, the bars or chocks 32 course, if a higher speed has been developed fulcruming on the ground, and the landing before the machine can start, and longer if gear will be lifted up precisely in the same a lower speed has been developed. Asthe manner as heretofore described until the machine jum s forward under the impetus wheels have vaulted over the obstruction, as of the prope er, the bars 17 will turn from it were. The adjustment of the device to their forwardly and downwardly inclined control the machine at different speeds is seposition to a downwardly and rearwardly cured by adjusting the bars or chocks 36 inclined position or that shown in Figure 3 longitudinally with reference to the link 30, and, of course, form no impediment to the and it is obvious that when the bolts 34 are movement of the wheels in any way and the disposed in the rearmost pair of holes in the machine then proceeds as usual. Preferbars 32 that the bars will be projected to the 11 ably the recesses 18 are formed with relagreatest extent and a greater speed will have tively contracted throats so as to form seats to be secured before the machine can poswithin which the axles 15 will rest, these sibly overleap this obstruction and pass onrecesses being thus formed so as to prevent ward and that when the bolts 31 are disthe movement of the axle out of the recesses posed in the lowest holes 34 a less speed will 12 without causing the lifting up of the chocks have to be secured.

or bars 17 and the consequent lifting up of Obviously many minor modifications. the machine and its landing gear. might be made without departing from the In Figures 4 and 5 I show another form spirit of the invention.

of the device which is simpler than that I claim z--- e 12: shown in Figure 1 but which operates on the 1. The combination with an aeroplane same general principle. The same reference having a propeller and including a transnumerals have been used for the parts of verse'rod, of means for detaining the mathe fuselage, landing wheels and struts. In chine until the propeller has reached a prethis form there is mounted upon the axle of determined speedincluding a pair of ground engaging bars mounted one on each side of the mac ine and normally extending downward and forward into engagement with the ground, each of said bars having a notch in which said transverse member en ages, and means pivotally supporting said ars upon the fuselage of the machine.

2. The combination with an aeroplane having a propeller, of means carried thereby and in an operative position preventing forward movement of the propeller under a speed less than a predetermined speed but shifted into inoperative position when the propeller has reached said predetermined speed, said means being adjustable to cause tie tripping of the means at any one of a number of predetermined speeds.

3. The combination with an aeroplane having a landing gear and a propeller, the landin gear including a transversely extending .ax e, of ground-engaging bars pivotally supported at their upper ends upon the aeroplane and when in operation extending downward and forward and intersecting the axle, the ground-en aging bars having each a plurality of note es to receive the axle and being transversely connected and said bars having a length from their pivotal axes to the ground-engaging ends of the bars greater than the distance from said pivotal axis vertically downward to theground, and springs acting to lift the bars into a rearward y extendin position when the s eed of the propeller ias forced the axle o the running gear out of said notches.

4. The combination with an aeroplane having ear having a transversely extending mem er, of means for detainin the machine until the propeller has reac ed a predetermined speed including a pair of groundengagin bars'm'ounted one on each side of the mac ine and, normally extending downward and forward into engagement with the ground and operatively supported for ivotal movement from a downwardly an forwardly inclined position rearward and upward in a vertica plane, springs urging t e forward ends of said bars downward and rearward, and meansfor supporting the transversely extending member of the anding a landing gear and a propeller, the land ing gear on said bars until the said bars are in their rearwardly directed position.

5. The combination with an aeroplane having a landing gear and a propeller, the landing gear having a transversely extending member, of means for detaining the machine until the propeller has reached a predetermined speed including a pair of ground-engaging bars mounted one on each side of the machineand normally extending downward and forward into engagement with the ground and operatively supported for ivotal movement from a downwardly an forwardly inclined position rearward and upward in a vertical plane, springs urging the forward ends of said bars downward and rearward, and links pivotally connected to the projecting members and pivotally connected each to one of said bars whereby to support the transversely extending member of the landing gear u on said bars until said bars have been turne into a rearward position.

6. The combination with an aeroplane having a landing gear and a propeller, the landing gear having a transversely extending mem er, of means for detainin the machine until the propeller has reache a predetermined s ed including a pair of ground-engaging ars mounted one on each side of the machine and normally extending downward and forward into engagement with the ground and operatively supported for (pivot a1 movement from a downwardly an for- -wardly inclined position rearward and u ward in a vertical plane, springs urging t e forward ends of said bars downward and rearward, links pivotally connected to the projecting members and pivotally connected each to one of said bars, each of said bars having a plurality of longitudinal] extending 0 enings, and a bolt disposab e in any one 0 said openings and pivotally connecting the bar to said link whereby to support the transversely extending member of the landing gear upon said bars until said bars have been turned into a rearward posltion.

In testimony whereof I hereunto aifix my signature.

SAMUEL S. HAWKINS. 

